I suppose I expected some kind of careful and considered response from the Sri Lankan government to the very serious evidence of war crimes and crimes against humanity we presented in our films about the last few bloody weeks of Sri Lanka’s terrible civil war. I should have known better. After all this was the government of a country in which dozens of journalists and media workers had died, disappeared or been forced into exile. Criticism is not tolerated.

In the last few years I have made several films investigating war crimes. Most of them about allegations of illegal behaviour, war crimes and extra-judicial executions by western governments. Two of them have indirectly resulted in – or contributed to - multi-million pound inquiries which have caused the British government considerable embarrassment. I make no apologies for that. It is my job.

But the response to our two films in the Sri Lanka’s Killing Fields series has been extraordinary.

As has been often said, this was supposed to be a war without witness: As the final assault got underway international staff of the UN were asked to leave the area, international media were allowed nowhere near, and internally all criticism was suppressed. Indeed Reporters without Borders named Sri Lanka as the fourth most dangerous country in the word to be a journalist.

Yet there were witnesses – there were people who kept a record. They were the victims and the perpetrators. Some of the footage and stills we used in our films was shot by doctors, some by civilians – but much of it was shot by Tiger cameramen and women; people who no doubt were expecting to produce propaganda about battles fought by LTTE fighters, but who instead ended up filming the unimaginable horrors experienced by civilians in the awful closing months. Horrors in which they were in part complicit – because as we made very clear in the films, despite what our critics say – the LTTE were also responsible for war crimes and crimes against humanity – and for using Tamil civilians as human shields.

And then of course there was the trophy footage. The deeply disturbing and triumphalist record of war crimes - extra judicial executions – and evidence of sexual assault and violence, carried out, and filmed, by the forces of the Sri Lankan government.

Channel 4 News had of course, already been covering the story – despite the difficulties – both in the final stages of the war and thereafter. Indeed the first video evidence of the execution of naked, bound prisoners by Sri Lankan forces appeared on Channel 4 News – supplied by Journalists for Democracy in Sri Lanka.

And then we put out our film. It was very carefully made, the evidence double checked and authenticated at every stage. It came out just after the report of the United Nations Panel of Experts had independently reached very similar conclusions about the evidence. And the reaction – partly because the evidence was so shocking, but also because it was so compelling – was extraordinary.

It was shown all over the world, debated in parliaments and governments from the UK to India, from Australia to the US – and of course Sri Lanka. It won awards and was even nominated for the Nobel Peace Prize. Along with the UN panel report and campaigning groups like Amnesty, HRW and the JDS, as well as the Tamil Diaspora, it helped ensure that these crimes were not forgotten – and made it more difficult for the world to continue to look away.

But it was the reaction of the Sri Lankan government which was most remarkable. It had several elements, many of them contradictory.

Their first reaction was simply to denounce the footage as fake. So I’d like to lay that claim to rest to start with.

We had the footage analysed by a team of independent and internationally respected technical video experts. They examined both the audio and video in minute detail for any evidence of faking, editing or manipulation. They found none. We also had an internationally respected forensic pathologist examine the footage of the injuries, the behaviour of the bodies, the nature and trajectory of the blood spatter and so on, to ensure it was consistent and not faked. The UN did the same, with different experts. They all reached the same conclusion – that there is nothing to be found anywhere that could suggest that the video records anything other than real executions shot in real time.

Of course the problem for the government is that they know the footage is not faked. In almost every shot you can see other soldiers filming – there is a wealth of video evidence and it continues to emerge. Indeed if these soldiers are as disciplined and organised as the government so often claims– and the government is determined to get to the truth - then the government would have long ago collected all this footage. If it showed that our footage was fake they would have released it. That they have not done so, speaks loudly.

(Of course in the row over the war crimes video, we shouldn’t forget the endless video evidence of crimes against humanity. The footage showing some of the tens of thousands of civilians who died under the government barrage on the government’s self-declared, so-called, no fire zones. The targeting of the hospitals which was identified by the UN panel report. The denial of food and humanitarian aid by the government. In our second film we examined four case histories in detail – tracing responsibility to the highest levels of the government and military. No-one has suggested we faked all that evidence as well.)

The second plank of the pro-government defence has been to suggest we are apologists for the LTTE. Indeed at one point it was even ludicrously suggested we had specifically been paid 5 million pounds to make the film. That is laughable nonsense. We were also accused of glossing over truths, such as the Tigers use of child soldiers and suicide bombers.

Okay, here’s a few lines from the script:

"The Tigers.. were a brutal army – often conscripting child soldiers and pioneering the use of suicide bombing."

"The Tamil Tigers were responsible for using this large civilian population as a shield, …. the Tamil Tigers were killing people to stop them from leaving..."

"There were more reports of cornered Tiger fighters firing on civilians who tried to escape…."

We showed footage which the government said was evidence of Tigers firing into the ground to prevent civilians from escaping – and images of the aftermath of LTTE suicide bombers.

But the Rajapaksa regime cannot hide behind the crimes of the Tigers. As Steve Crawshaw of Amnesty said in the film, the crimes of one side do not justify the crimes of the other. Especially when that other side claims to be a democratic government which has signed up to, and respects international law.

The problem for the Rajapaksas is that they know only too well that they have in practice shown complete contempt for the rule of international law. The evidence is there for all to see – and with every day that passes that evidence becomes more compelling. But they know they cannot win if the truth comes out, so they are trapped in an increasingly unsustainable pattern of denial, delay (through meaningless inquiries), and outright repression.

On the international level they have tried to confuse the issue by hiding behind claims that this is some kind of western conspiracy to attack the sovereignty of a small developing nation. This is just so much claptrap.

(And I shall leave aside the absurd suggestion that while spending so much of my career exposing the crimes of Western governments I was secretly an agent for them – and simultaneously an agent for the LTTE as well of course!)

In fact throughout the war it was the Rajapaksa regime which used the West’s language of the ‘Global War on Terror’ to justify the ruthlessness of the offensive against the Tigers and, by extension, the Tamil civilians who were trapped with them in the so-called No Fire Zones. Indeed as we clearly revealed in our second film, there was a tacit acceptance by the West – and indeed most of the international community and the UN - that while occasionally protesting, they would not actually do anything to stop the carnage. It is only in the aftermath, as the true scale of the massacres continues to emerge, that countries ranging from the US to India have been forced to seriously engage with the notion that justice must be done and the war crimes must be investigated.

But there are probably two particular things which illustrate the hypocrisy of the government’s claims that they are the victims of a ‘western’ conspiracy.

The first is Mahinda Rajapaksa’s speech to the UN in 2010. It was in that speech that he first warned the rest of the world to back off.

He told the UN: “If history has taught us one thing, it is that imposed external solutions breed resentment and ultimately fail. Ours, by contrast, is a home grown process, which reflects the culture and traditions of our people.”

But the second, and far more important, illustration of just how hypocritical is this claim that Sri Lanka is an innocent nation being victimised by the West, is the regime’s terrifying ramping up of the repression of its own people. While thousands of Tamils from the North East remain homeless, the military builds barracks and seizes land. Local Tamil people are subjected to political repression, economic marginalisation and a regime of violence and intimidation. Throughout the country the military consolidates its power. While even the Lessons Learnt and Reconciliation Commission calls for the military to disengage from civilian administration, the government hands the absurdly renamed ‘Ministry of Defence and Urban Development’ yet more lucrative construction contracts in Colombo and elsewhere.

Meanwhile the sinister spate of ‘White Van’ abductions of government critics, both Sinhala and Tamil, grows.

The government may attempt to claim that they are being threatened by a ‘western conspiracy’ – in fact it is clear that what they really fear is their own people, the Sri Lankan independent media, the Tamils, Sinhala critics and pro-democracy campaigners.

And even more they fear that the truth will out about the war crimes and crimes against humanity which occurred under their watch.

They know that the investigation of war crimes - and the demand that justice must follow - is a international obligation, not a western conspiracy. Indeed the Sri Lankan government itself - quite correctly - called for an investigation into the circumstances surrounding the death of Mahinda Rajapaksa’s former ally, Col Muammar Gaddafi of Libya.

So by the same token will the Sri Lankan government accept that if they themselves fail, then the world has the right - and indeed the duty – to investigate war crimes wherever they happen, and to call to account governments that fail so to do?

We shall see.

Callum Macrae is a journalist and filmmaker who has filmed and directed many award-winning television documentaries for Channel 4 and the BBC. His works include Iraq's "Mission Billions" - a 'Dispatches' investigation filmed in the US and Iraq, into Coalition misuse of billions of dollars of Iraqi funds. He is the Director of "Sri Lanka’s Killing Fields", an investigatory documentary about the final weeks of the Sri Lankan Civil War.

JDS is the Sri Lankan partner organization of international media rights group, Reporters Without Borders (RSF). The launching of this website was made possible by the EU’s European Instrument for Democracy and Human Rights (EIDHR), of which Reporters Without Borders is a beneficiary.